Evaluation of a surface permanent magnet helical motor with high precision teeth

A helical motor is an axial gap helical motor with a stator that consists of windings and teeth made of soft magnetic composite. The teeth of a previously developed helical motor were of low precision owing to the manufacturing method. The low-precision teeth affected the motor performance negatively. In this study, we proposed a new type of a helical motor with high-precision teeth; furthermore, we evaluated its magnetic levitation control, zero-power control, position control, and frequency response. We found that less current was required for the magnetic levitation control and the accuracy of the position control improved because of broadening of the stable band.